The present invention relates to novel compounds DC-89A2, DC-89B1 and DC-89B2, which are generically referred to as DC-89 compounds hereinafter, and to processes for preparing the DC-89 compounds and a known compound DC-89A1. The DC-89 compounds of the present invention have antibacterial and anti-tumor activity and are useful as antibacterial and anti-tumor agents.
As the low-molecular substances having antibacterial and anti-tumor activity and obtained from microorganisms or plants, many compounds such as anthracycline compounds, anthraquinone compounds and mitomycin compounds have so far been reported (CRC Handbook of Antibiotic Compounds, CRC Press, U.S.A., 1981).
Further, as the compounds analogous to the DC-89 compounds, DC-88A and DC-89A1 which have antibacterial and anti-tumor activity and which are produced by microorganisms belonging to the genus Streptomyces are disclosed in WO 87/06265 (EP-A-0271581).